Release notes at doc website https://developer.apple.com/documentation/appstoreconnectapi/app_store_connect_api_release_notes/app_store_connect_api_version_2_1_release_notes
says that I need to update my server-side code to use new features
App Store Connect API version 2.1 release notes
Update your server-side code to use new features, and test your code against API changes.
But what exacly I need to update?
Thanks!